Fermented Milk



Fermented milk products are created when milk ferments with lactic acid bacteria, such as Lactobacilli or Bifidobacteria spp. The fermentation process makes the fermented milk product easier to digest, especially for people who have milk allergies or are lactose-intolerant. Fermentation also increases the shelf-life of the milk product.

People take fermented milk by mouth for diarrhea caused by rotavirus, hay fever caused by ragweed, diarrhea caused by antibiotics, arthritis, asthma, biliary disorders, bladder cancer prevention, breast cancer, child growth, colitis, colon cancer prevention, constipation, Crohn's disease, dental cavities, diabetes, diarrhea, indigestion, gas, gallbladder disease, stomach cancer, stomach flu, gastroesophageal reflux disease (GERD), Helicobacter pylori (H. pylori) infection, high cholesterol, high blood pressure, inflammatory bowel disease, irritable bowel syndrome (IBS), iron deficiency anemia, heart disease, Japanese cedar pollinosis, lactose intolerance, obesity, osteoporosis, infection of the pancreas, stomach ulcers, inflammation in an artificial rectum created after surgery for ulcerative colitis (pouchitis), side effects cause by radiation that affect the stomach, respiratory tract infections, tuberculosis, ulcerative colitis, and urinary tract infections (UTI).

People apply fermented milk to the skin for canker sores, sunburn, skin ulcers, vaginitis, and wrinkled skin.

How it works

Fermentation of milk involves adding lactic acid bacteria to the milk product. The bacteria break down milk proteins. This helps people with allergies to milk protein digest milk. Also, the bacteria break down lactose. This helps people who are lactose intolerant digest milk. Fermented milk also seems to help lower blood pressure, lower cholesterol, and prevent cancer from growing. These improvements might be due to the antioxidant or immune-stimulating effects of fermented milk products.


Possibly Effective
Diarrhea caused by rotavirus

Some evidence suggests that drinking a fermented milk product containing Lactobacillus GG for about 5 days reduces the duration of diarrhea in children with diarrhea caused by rotavirus.

Hay fever caused by ragweed

Some research shows that drinking fermented milk containing Lactobacillus acidophilus can reduce nasal, but not eye-related symptoms, associated with hay fever in adults. Other research suggests that drinking fermented milk containing other types of Lactobacillus bacteria as well as Streptococcus thermophiles might decrease the occurrence of hay fever in both children and adolescents. However, some conflicting evidence exists.

Diarrhea caused by antibiotics

Some evidence shows that taking fermented milk containing Lactobacillus and Bifidobacterium species by mouth daily reduces the risk of developing diarrhea while taking antibiotics. Other research suggests that taking fermented milk containing two Lactobacillus species by mouth daily for 2 days and continuing until the end of antibiotic treatment reduces the risk of developing diarrhea in people who are hospitalized.


Early research suggests that drinking milk fermented that contains Lactobacillus casei for one month reduces the severity of diarrhea in infants and children. There is mixed evidence about whether drinking this fermented milk reduces the number of times that diarrhea occurs in infants and children. Other early research shows that using a specific fermented milk product (Actimel) containing Lactobacillus casei, Lactobacillus bulgaricus, and Streptococcus thermophiles reduces the length of time needed to stop diarrhea in children 6 months to 5 years-old.

Ulcers caused by a bacterium called Helicobacter pylori (H. pylori)

Research shows that drinking a fermented milk beverage containing Streptococcus thermophiles and Bifidobacterium bifidum or Lactobacillus johnsonii daily for 12-16 weeks improves stomach symptoms caused by H. pylori infection. Other research shows that adding a specific fermented milk product (Actimel) to standard antibiotic therapy improves H. pylori infections faster than antibiotics alone.

Lactose intolerance

Some research shows that taking fermented milk containing Lactobacillus casei and Lactobacillus acidophilus reduces bloating, diarrhea, and pain in people with lactose intolerance. Other research suggests similar effects when fermented milk products are consumed by lactase-deficient people along with meals that contain lactose.

High blood pressure

Some evidence shows that taking tablets containing powdered fermented milk by mouth for 4 weeks lowers systolic but not diastolic blood pressure in people with high blood pressure. Other research shows that taking a fermented milk product containing gamma-aminobutyric acid (GABA) by mouth for 12 weeks decreases blood pressure in women with slightly high blood pressure.

Irritable bowel syndrome (IBS)

Some early research suggests that drinking a specific probiotic fermented milk (AB100, Jiannend, Bright Dair, Shanghai, China) twice daily for 4 weeks decreases IBS symptoms, including pain and gas. Other research found similar findings for another fermented milk product (Activia, Danone) containing Bifidobacterium animalis.

Gastrointestinal radiation side effects

Research suggests that drinking fermented milk containing Lactobacillus acidophilus daily for 5 days before radiotherapy and continuing for 10 days after reduces diarrhea and other stomach side effects caused by radiation. Other research suggests that drinking fermented milk containing Lactococcus species might improve stomach discomfort after radiation of the pelvic area.

Inflammatory bowel disease (ulcerative colitis)

Some research shows that drinking fermented milk containing Bifidobacterium breve, Bifidobacterium bifidum, and Lactobacillus acidophilus daily for up to one year decreases ulcerative colitis symptoms.


Likely safe

Fermented milk is LIKELY SAFE when taking by mouth in amounts commonly found in foods

Possibly safe

Fermented milk is POSSIBLY SAFE when taking by mouth in amounts used for medicine for up to one year. There is not enough information available to know if fermented milk is safe when applied to the skin.



Pregnancy and breast-feeding: There is not enough reliable information about the safety of taking fermented milk if you arepregnantor breast-feeding. Stay on the safe side and avoid using in amounts greater than those commonly found infood.

Children: Fermented milk is LIKELY SAFE when taking by mouth in amounts commonly found in foods. Fermented milk is POSSIBLY SAFE when taken by mouth in medicinal amounts for up to 5 days.

Low blood pressure: Fermented milk might reduce blood pressure. In theory, taking fermented milk might cause blood pressure to become too low when used by people who already have low blood pressure.

Weakened immune system: Some fermented milk products contain live bacteria. There is some concern that the bacteria in fermented milk might grow too well in people whose immune systems are weakened. This includes people with HIV/AIDS or people who have taken medicines to prevent rejection of a transplanted organ. Lactobacillus, one type of bacteria found in fermented milk products, has caused disease (rarely) in people with weakened immune systems. To be on the safe side, if you have a weakened immune system, talk with your healthcare provider before taking fermented milk products.


Always consult with your doctor.
Antibiotic drugs

Antibiotics eradicate many different types of bacteria. Fermented milk products contain some types of bacteria. Taking antibiotics with fermented milk might eradicate the bacteria in fermented milk. This might decrease how well the fermented milk product works. To avoid this, antibiotics and fermented milk should be taken at least 2 hours apart.

The information provided on this page is for reference purposes and is not meant to be used as a medical advice, diagnosis or treatment. Always consult with a medical professional.